A Battered but Unbowed Justin Trudeau Vows to Stay the Course in Canada

His objective now, he said, is to allow anyone with a concern “to actually articulate that to me, and quicker, so we can respond to it rather than let it sort of fester the way apparently it did here.”

Mr. Miller, his friend, said the prime minister had learned that it was important to be open “to a number of voices that you don’t necessarily want to hear but you have to for your own development.”

Mr. Trudeau is also fighting back against his critics, for example, threatening to sue Mr. Scheer, for suggesting that he acted criminally.

“The fact that he has been doing that and thinks he can get away with that is one of those things that we have to push back against,” Mr. Trudeau said.

As he looked back on a winter that turned him from front-runner to underdog, Mr. Trudeau predicted that by October the nation’s political focus will have returned to what he called “the big things, whether it’s environment or climate or growth for the middle class.”

Rejecting any suggestion that with several provinces having swung from left-of-center governments to ones led by conservatives, liberalism is on the wane in Canada or the rest of the world, Mr. Trudeau pointed out that he was followed to power by ideologically sympathetic leaders in France, Spain and New Zealand.

“There were good moments and tough moments,” he said of the election year’s rocky start. “But ultimately the opportunity to make a meaningful, positive difference in Canadians’ lives with what we do every day here is just unbelievably gratifying and worth it for all the guff you have to go through.”